Average Height Of Ghana Male And Female

This West African country, is not the land of midget, but they are short. Yes you’ll see tall people both male and female, but when compared to the population of Ghana, this men and women becomes just like a pin in a hay. In other words tall people in Ghana are few.
It has been reported that Ghanain are 159.3 cm (5 ft21⁄2in) tall on the average.
But according to measurement, measured in 1989 and available in wikepeadia, Ghanains measured 169.5 cm (5 ft61⁄2in) in male and 158.5 cm (5 ft21⁄2in) in female.
Is it to say that this West African country is getting shorter as the years roll by?